1. Field of the Invention
The present invention relates to a system for limiting an increase in the inside air temperature of a passenger compartment of a vehicle.
2. Description of Related Art
One previously proposed system for limiting an increase in the inside air temperature of a passenger compartment of a vehicle held in a parked state includes a ventilation fan, which is powered by a solar battery to expel hot air out of the passenger compartment of the vehicle. One such system is disclosed in, for example, Japanese Unexamined Patent Publication No. 5-244731.
However, in general, production of electricity from the solar battery is relatively small in comparison to production of electricity from an electric generator driven by a vehicle engine. Thus, the ventilation fan powered by the solar battery cannot efficiently expel the hot air out of the passenger compartment of the parked vehicle.
One calculation result indicates that the exhaust fan powered by the solar battery can reduce the inside air temperature of the passenger compartment only by 8 degrees Celsius at most. Thus, under the blazing sun in the summer where the inside air temperature of the vehicle reaches about 50 degrees Celsius, the invention disclosed in Japanese Unexamined Patent Publication No. 5-244731 cannot sufficiently reduce the inside air temperature of the passenger compartment.
Furthermore, according to the invention disclosed in Japanese Unexamined Patent Publication No. 5-244731, only the ventilation of the hot air from the passenger compartment through use of the ventilation fan powered by the solar battery is performed. Thus, due to, for example, radiation heat from interior members, such as seats, an instrument panel, and interior walls (interior trim), each of which has a relatively large thermal capacity, the inside air temperature of the passenger compartment may be increased once again. Thus, an increase in the inside air temperature of the passenger compartment of the parked vehicle cannot be efficiently limited.